The Golden Quartet

Aegislash @ Leftovers
Ability: Stance Change
EVs: 252 HP / 4 Def / 252 SpD
Sassy Nature
- King's Shield
- Gyro Ball
- Toxic
- Pursuit

Talonflame @ Life Orb
Ability: Gale Wings
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Brave Bird
- Flare Blitz
- Roost
- Will-O-Wisp

Greninja @ Expert Belt
Ability: Protean
EVs: 4 HP / 252 SpA / 252 Spe
Timid Nature
- Hydro Pump
- Grass Knot
- Dark Pulse
- Ice Beam

Breloom @ Focus Sash
Ability: Technician
EVs: 252 HP / 252 Atk / 4 SpD
Adamant Nature
- Bullet Seed
- Mach Punch
- Drain Punch
- Spore

Groudon-Primal @ Red Orb
Ability: Desolate Land
EVs: 252 HP / 252 Atk / 4 SpD
Adamant Nature
- Precipice Blades
- Fire Punch
- Stone Edge
- Stealth Rock

Xerneas @ Power Herb
Ability: Fairy Aura
EVs: 248 HP / 252 SpA / 8 SpD
Modest Nature
IVs: 0 Atk
- Geomancy
- Moonblast
- Thunder
- Focus Blast